Method and apparatus for continuously excavating particulate material and converting it to slurry

ABSTRACT

A continuously operating means excavates gravel, ore or a like particulate material from the earth and drops it onto an inclined grate having large openings. The grate retains rocks and other non-pumpable material, and the balance of the particulate material drops into a hopper fitted with a traveling water jet in the bottom thereof that converts the material within its vicinity to a slurry. The slurry flows from the hopper into a sump and is pumped by pump means from the sump through transfer conduits to a point of discharge.

llnited States Patent [191 Sims et-al.

[451 May 28, 1974 METHOD AND APPARATUS FOR CONTINUOUSLY EXCAVATING PARTlCULATE MATERIAL AND CONVERTING IT TO SLURRY [75] Inventors: Wilbert Norman Sims, Alamo; John A. Miscovich, Orange, both of Calif.

[73] Assignee: Marcona Corporation, San

Francisco, Calif.

22 Filed:-' Nov. 22, 1972' 21 Appl.No.:308,772

52 us. Cl. 299/7, 308/14 [51] Int. Cl E021 3/94 [58] Field of Search..... 299/7; 302/15, 14, 16

[56] References Cited UNITED STATES PATENTS 8/1950 Lyons et a1. 299/7 X 2,791,472 5/1957 Barthauer ct a1. .7 302/14 X 3,168,350 2/1965 Phinney et al.. 302/14 3,729,232' 4/1973 Sakata et a1, 302/15 FOREIGN PATENTS OR APPLICATIONS 599,991 11/1959 Italy 299/7 Primary Examiner-Ernest R. Purser [57] ABSTRACT A continuously operating means excavates gravel, ore or a like particulate material from the earth and drops it onto an inclined grate having large openings. The grate retains rocks and other non-pumpable material, and the balance of the particulate material drops into a hopper fitted with a traveling water jet in the bottom thereof that converts the material within its vicinity to a slurry. The slurry flows from the hopper into a sump and is pumped by pump means from the sump through transfer conduits to a point of discharge.

8 Claims, 3 Drawing Figures BACKGROUND OF'THE INVENTION 1. Field of the Invention Thepresent invention relates generally to the excavation of gravel, ore and like particulate material. More particularly, it relates to a method and apparatus for 1 Another object is to'provide a method and apparatus for taking freshly excavated particulate material and continuously converting it into a pumpable slurry.

continuously excavating particulate material, convertsite, and damage to the environment commonly results because of such construction and the accompanying movement of the heavy vehicles. In addition, the operation of such a system requires considerable human labor, and the operation expenses for the vehicles canbe large.

Because of the problemsnoted herein and others, a new system for excavating material and moving it away from the excavation site isdesirable. The method and apparatus of the present invention constitute such a system, one that is continuous in operation and which requires a minimum-of labor and auxiliary equipment.

SUMMARY OF TI-IE INVENTION AND OBJECTS Inthe present invention gravel or other particulate material is excavated and delivered through an inclined upper grate or coarse screen into a materials holding hopper, the inclined grate serving to take out rocks and other materials that cannot be easily converted into a pumpable slurry. Disposed within the lower end of the hopper is a traveling water jet that directs at least one Other objects and many of the attendant advantages of the present invention will become readily apparent from the following detailed description of the preferred embodiment, when taken together with the accompanying drawings.

BRIEFDESCRIP'TION OF THE DRAWINGS I FIG. 1 is a side elevational view of the machine of the invention, shown in operation excavating particulate material and converting the material into a pumpable slurry; 1

FIG. 2 is an enlarged, plan view of the machine of FIG. 1, taken along the line 2 2 of FIG. 1, and showing details of the construction thereof; and

FIG. 3 is an enlarged, fragmentary, partially broken away view taken along the line 3-3 in FIG. 2, and showing the inclined upper grate or coarse screen, the materials hopper, and the traveling water jet in operation continuously processing freshly excavated material into a pumpable slurry.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The method of the present invention includes the successive steps of excavating particulate material from the earth, and feeding the freshly excavated material by gravity into a materials hopper through" an inclined upper grate or coarse screen that takes out rocks and other materials that are not easily converted into a slurry. The screened material is then converted to a slurry within the lower part of the materials hopper by a traveling water jet that is directed generally parallel to and just above the bottom wall of the hopper, the slurry flowing out of the hopper by gravity through a grate into a sump. Finally, the slurry is pumped from the sump, and transmitted to a desired discharge point by conduits of suitable length.

Referring now to the drawings, the excavating machine of the invention is indicated generally at 2, and

includes a main structural truss frame 4 mounted on stream of high pressure water generally parallel to the bottom wall of the hopper, which water jet acts on the screened particulate material layer lying at the bottom of the hopper to convert it into a slurry. The slurry then flows out of the hopper through a lower grate and into a sump, from where it is drawn by a pump that pumps the slurry through a conduit to a point of discharge.

In the preferred form of the invention a continuous bucket line is utilized to excavate the particulate material, although the present method and apparatus are adaptable to other excavating devices. The coarse materials taken out by theinclined upper grate or coarse screen are collected by the machine, and are discharged by a conveyor belt into a slag pile. The machine itself is mounted on tracks or the like, and is fully maneuverable.

It is the principal object ofthe present invention to provide a method and apparatus whereby gravel and like particulate material can be takenand continuously processed into a slurry, all within a single maneuverable machine without the need for auxiliary vehicles at the excavation site.

conventional tracked crawlers 6 for moving the machine 2 across the surface 8 of the earth. Mounted on top of one end of the main frame 4 above one of the crawlers 6 is a swing base 10 for receiving and rotatably mounting a bull wheel 12, the latter supporting a materials hopper 14 having an operators cab 16 mounted on the upper end thereof. A motor 18 is mounted on the frame 4 centrally thereof, and is connected with the central portion of a swing chain 20 that engages the periphery of the bull wheel 12, whereby the wheel and the equipment mounted thereon can be rotated. The extend of such rotation will usually be limited to about and a safety cutout will be associated with the swing chain 20 to stop the motor 18 before the designed degree of rotation is exceeded. It is of course understood that other arrangements for driving the bull wheel 12 can be devised.

The upper surface of the bull wheel 12 has spaced bushings 22 thereon on opposite sides of the hopper 14, to which the lower ends of the side members 24 of a gantry frame 26 are pivotally connected by pins 28. The upper end of the gantry frame 26 carries a transverse member 30, to the opposite ends of which are connected to elbow central portions of L-shaped arms 32. The rearwardly directed ends of the L-shaped arms 32 are connected by cables 34 to anchors 36 on the top of the cab 16, whereby to support the gantry frame 26.

Mounted transversely within the forward section of the cab is a drive tumbler 38, connected through a clutch mechanism operated from the cab 16 to a motor. The tumbler 28 is carried on a cross shaft 40, and mounted to pivot about the axis of said shaft is the upper end of a ladder 42 that carries an idler tumbler 44 at its outer end, and which supports a continuous chain of excavator buckets 46. Near its outer end the bucket ladder 42 has the lower end of a bracket 48 pivoted thereto, the upper end of said bracket and the lower ends of the L-shaped arms 32 being connected by a tackle assembly 50 connected to a hoist winch and motor 52 mounted on a platform 54 carried by the gantry frame 26.

The upper or drive tumbler 38 is a six-sided drum or sprocket, and engages the flat back walls 56 of the buckets 46 to drive the bucket chain, the buckets 46 being pivotally connected to each other by pins 58. The hoist winch and motor 52 is preferably operated by oil pressure to give a smooth variable speed and a positive lock in the Off position, although an electric motor can be used, if desired. Generating equipment 60 is located within the cab 16, to generate the oil pressure and/or electrical energy required to operate the machine 2, it being contemplated, however, that when such is available electrical energy will be drawn from nearby service lines.

In order to give some added stability to the rotating cab 16 and bin 14, and to provide a safe and effective means for transmitting electrical energy to the machine 2, a shaft bearing 62 projects from the top of the cab 16 on the centerline of the bull wheel 12, and is received within a bushing 64 carried on one end of an arm 66 supported by an upright frame 68 mounted on the main frame 4. Electrical conductors 70 are carried by the frame 68 and the arm 66, and enter the cab 16 in the area of the bearing 62, it being understood that hydraulic lines can also be installed in the same manner. The conductors 70, and any similarly located hydraulic lines, are supported by the frame 68 and the arm 66, and are thus held away from the areas where damage thereto might occur. The conductors 70 lead from a transformer 71 and switching gear 73 carried by the main frame 4, and hydraulic pressure for powering the crawlers 6 and/or other components of the machine 2 is supplied by a generator 75.

The hopper 14 is generally rectangular in configuration, and includes a bottom wall 72 that is gently sloped toward a central opening 74, a mounting flange 76 being secured to the underside of the bottom wall 72, and the bull wheel 12 having a central opening therein to accommodate the mounting flange 76. A sump 78 is carried by the main frame 4 below the hopper 14, and has a flange 80 on the upper end thereof that telescopically receives a collar 82 carried by the mounting flange 76. Bearings 84 are disposed between the mounting flange 76 and the upper face of the flange 80 to form a freely rotatable joint, and a seal 86 is carried within a groove in the flange 80 and engages the collar 82.

The mounting flange 76 carries a lower grate 88 having a central opening therein beneath which a mounting collar 92 is supported by webs 94 from the collar 82. The sump 78 includes an inclined bottom wall 96 having an opening 98 therein located directly below the mounting collar 92, and extending upwardly through said opening 98 is a mounting cylinder 100.

The mounting cylinder 100 is secured to the sumps inclined bottom wall 78 by a mounting plate 102, and the upper end thereof is received within the mounting collar 92. Extending through the mounting cylinder 100 and rotatably mounted therewithin is a hollow shaft or pipe 104 having an enlarged head 106 on its upper end, the head 106 having a gently tapering conical upper surface. Mounted on the shaft 104 beneath the lip of the enlarged head 106 and above the upper end of the mounting cylinder 100 is at least one nozzle 108, arranged to direct a jet of water generally parallel to the bottom wall 72 of the materials hopper 14.

Water is supplied to the lower end of the pipe 104 through a rotating joint structure 110 from a supply conduit 112, the joint structure 110 including a gear arrangement driven by a motor to constantly rotate the pipe 104 during operation of the machine 2. The water supply conduit 112 leads to a high pressure pump 114 carried by the main frame 4 and powered by a motor 116, which arrangement eliminates the need for a high pressure water line being extended to the work location of the machine 2. The traveling water jet structure just described is similar to that which was the subject of US. Pat. No. 3,606,479, reference to which can be made for a more detailed description thereof.

Mounted above the bottom wall 72 within the materials hopper 14 is an inclined upper grate or coarse screen 118, the upper edge thereof being located near the top of the hopper l4, and the central portion of the grate being disposed directly below the discharge end of the excavator bucket line. The purpose of the inclined grate 118 is to screen out rocks, debris and other coarse foreigh matter that cannot be easily reduced to a pumpable slurry, such screenings dropping by gravity off the forward end of the inclined grate 118 onto a chute 120 arranged to discharge them onto a conveyor 122 that extends transversely of the machine 2 along the lower front edge of the hopper 14, the conveyor 122 delivering the screenings to a slag pile.

The particulate material passing through the inclined upper coarse grate or screen 118 falls into the materials hopper 14 and onto the bottom wall 72 thereof, the openings in the lower grate 88 being sufficiently small so that the dry particulate material that accumulates within the hopper 14 does not fall through said lower grate to any extent. The traveling water jet 108 directs a jet of high pressure water into the accumulated particulate material layer lying on the bottom wall 74, and acts to convert the material into a slurry that falls by gravity through the lower grate 88 into the sump 78. The sump 78 has an outlet 124 is the lower end thereof that is connected through a gate valve 126 to the inlet of a slurry pump 128 mounted on the main frame 4, and driven by an engine 130. An intermediate discharge line 132 is connected to the outlet of the slurry pump 128, and extends through the main frame 4 to the rear end thereof, where it is connected to a final discharge conduit 134. The outer end of the conduit 134 is carried by a dolly 136, and conduits 138 of any desired length can be connected to the conduit 134 to carry away the slurry, within the transfer capacity of the pump 128.

- .5 a The pipe 104 is rotated slowly within the cylinder 100, say at a speed of as low as a fraction of an rpm. up to around 6 rpm. or so, and the water supplied to the nozzle 108 will be at a high pressure, say around 300 p.s.i.g. The water jet, as has been described, is aimed generally parallel to the bottom wall 72 of the hopper l4, and is directed into the lower or bottommost layer of particulate material lying on said wall.

.When the jet stream impacts upon the bottommost layer of particulate material, such is broken up and be- I comes suspended in the water as a slurry. As the slowly rotating nozzle l08'moves away from the impacted area, the freshly formed slurry will flow through the lower grate 88 into the sump 78, and will be replaced on the bottom wall '72 of the hopper 14 by the relatively dry material thereabove. Thus, the traveling jet is effective to continuously produce slurry, the space vacated just above the bottom wall when the slurry flows into the sump 78 being taken up by fresh or relatively dry particulate material that moves thereinto from above.

it is thus seen that there has been disclosed a method and apparatus for the continuous production of slurry from gravel, ore or other material excavated from the earth. Obviously, many variations and modifications of the present invention are possible.

What I claim is: a

1. Method of producing slurry from excavated particulate material, comprising the steps of:

a. excavating substantially dry particulate material from the earth using a continuous bucket excavator; v

b. transporting the excavated particulate material to a material hopper with the continuous bucket excavator;

c. dropping the particulate material vertically onto an inclined grate in the material hopper;

d. screening the particulate material with the inclined grate on said material hopper, thereby removing material larger than a predetermined size therefrom; a

e. slurrifying the screened particulate material within the material hopper having passes through the screen with a high velocity, rotating water jet;

f. separating theslurry from the dry particulate material thereabove with a grate located in the bottom of the material hopper;

g. retaining the dry particulate material within the material hopper until slurrified; and

h. removing the slurry from the material hopper and pumping the same to a destination removed from said excavation with a slurry pump and pipeline.

2. Method of producing slurry from excavatable particulate material using a mobile plant, comprising the steps of:

a. maneuvering the mobile slurry producing plant into position on the earth proximate to the particulate material therein;

b. engaging the particulate material with a'continuous bucket excavator mounted on the mobile plant;

c. excavating the particulate material from the earth using the bucket excavator; d. conveying the excavated, Particulate material to the mobile plant;

e. removing any large rocks from the particulate material with an inclined grate mounted on the top of a material hopper on the mobile plant;

f. depositing the particulate material into the material hopper on the mobile plant;

g. converting the bottommost layer of particulate material in the material hopper into a slurry with a high velocity water jet; and

h. pumping the slurry out of the material hopper to a selected point of discharge from the mobile plant.

3. The method as recited in claim 2, wherein said step of converting the bottommost layer of particulate material within said hopper into a slurry includes: directing a high pressure jet of water generally parallel to the bottom wall of said hopper and into said bottommost layer of particulate material; and rotating said water jet about a vertical axis, whereby such will progressively engage the particulate material, and whereby the slurried material behind the rotating jet isfreed to flow out of the hopper.

4.'Apparatus for producing slurry from particulate material excavated from the earth, comprising:

a. a mobile supporting vehicle having tracks thereon for traversing the earth;

a continuously operable bucket excavatorconveyor attached to the supporting vehicle for re moving said particulate material from the earth and for transporting said material to the supporting vehicle;

c. a material hopper disposed on the supporting vehicle for receiving the particulate material from the excavator-conveyor and having a bottom wall thereto;

d. an upper separating grate mounted on said material hopper in the path of material falling off the excavator-conveyor outlet for separating any rocks larger than a predetermined size from the particulate material;

e. means within the lower end of said hopper for converting the particulate material therein into a slurry;

, f. a lower separating grate mounted on said material hopper'below said slurry converting means for separating the slurry from the particulate material and for retaining the particulate material within the material hopper until converted into slurry; and

g. a discharge sump below the material hopper for receiving the slurry from the hopper.

5. Apparatus of claim 4 further including:

a. a discharge chute disposed along the lower edge of the upper separating grate for receiving the rocks separated from the particulate material by said grate; and

b. a discharge conveyor transversely disposed on a mobile supporting platform, in communication with the discharge chute for receiving the rocks therefrom, and terminating for discharge at a point laterally disposed from the mobile supporting platform, whereby large rocks separated from the particulate material are removed clear and away from the bucket excavator.

6. Apparatus as recited in claim 4, including means for pumping said slurry from said sump.-

7. Apparatus as recited in claim 4, wherein said means for converting said particulate material into slurry includes: nozzle means mounted for rotation said mounting cylinder, and having an enlarged head on the upper end thereof, the lower end of said hollow shaft extending to the exterior of said sump, and said enalarged head being disposed above said hopper bottom wall; and connector means rotatably mounted on said extended lower end of said hollow shaft for transmitting high pressure water thereto, said nozzle being mounted on said hollow shaft below said enlarged head and being in communication with said connector means. 

1. Method of producing slurry from excavated particulate material, comprising the steps of: a. excavating substantially dry particulate material from the earth using a continuous bucket excavator; b. transporting the excavated particulate material to a material hopper with The continuous bucket excavator; c. dropping the particulate material vertically onto an inclined grate in the material hopper; d. screening the particulate material with the inclined grate on said material hopper, thereby removing material larger than a predetermined size therefrom; e. slurrifying the screened particulate material within the material hopper having passes through the screen with a high velocity, rotating water jet; f. separating the slurry from the dry particulate material thereabove with a grate located in the bottom of the material hopper; g. retaining the dry particulate material within the material hopper until slurrified; and h. removing the slurry from the material hopper and pumping the same to a destination removed from said excavation with a slurry pump and pipeline.
 2. Method of producing slurry from excavatable particulate material using a mobile plant, comprising the steps of: a. maneuvering the mobile slurry producing plant into position on the earth proximate to the particulate material therein; b. engaging the particulate material with a continuous bucket excavator mounted on the mobile plant; c. excavating the particulate material from the earth using the bucket excavator; d. conveying the excavated, particulate material to the mobile plant; e. removing any large rocks from the particulate material with an inclined grate mounted on the top of a material hopper on the mobile plant; f. depositing the particulate material into the material hopper on the mobile plant; g. converting the bottommost layer of particulate material in the material hopper into a slurry with a high velocity water jet; and h. pumping the slurry out of the material hopper to a selected point of discharge from the mobile plant.
 3. The method as recited in claim 2, wherein said step of converting the bottommost layer of particulate material within said hopper into a slurry includes: directing a high pressure jet of water generally parallel to the bottom wall of said hopper and into said bottommost layer of particulate material; and rotating said water jet about a vertical axis, whereby such will progressively engage the particulate material, and whereby the slurried material behind the rotating jet is freed to flow out of the hopper.
 4. Apparatus for producing slurry from particulate material excavated from the earth, comprising: a. a mobile supporting vehicle having tracks thereon for traversing the earth; b. a continuously operable bucket excavator-conveyor attached to the supporting vehicle for removing said particulate material from the earth and for transporting said material to the supporting vehicle; c. a material hopper disposed on the supporting vehicle for receiving the particulate material from the excavator-conveyor and having a bottom wall thereto; d. an upper separating grate mounted on said material hopper in the path of material falling off the excavator-conveyor outlet for separating any rocks larger than a predetermined size from the particulate material; e. means within the lower end of said hopper for converting the particulate material therein into a slurry; f. a lower separating grate mounted on said material hopper below said slurry converting means for separating the slurry from the particulate material and for retaining the particulate material within the material hopper until converted into slurry; and g. a discharge sump below the material hopper for receiving the slurry from the hopper.
 5. Apparatus of claim 4 further including: a. a discharge chute disposed along the lower edge of the upper separating grate for receiving the rocks separated from the particulate material by said grate; and b. a discharge conveyor transversely disposed on a mobile supporting platform, in communication with the discharge chute for receiving the rocks therefrom, and terminating for discharge at a point laterally disposed From the mobile supporting platform, whereby large rocks separated from the particulate material are removed clear and away from the bucket excavator.
 6. Apparatus as recited in claim 4, including means for pumping said slurry from said sump.
 7. Apparatus as recited in claim 4, wherein said means for converting said particulate material into slurry includes: nozzle means mounted for rotation within the lower end of said hopper, and including at least one nozzle aimed generally parallel with the bottom wall of said hopper and into the bottommost layer of any particulate material lying on said bottom wall; means for rotating said nozzle means about a vertical axis; and means for supplying high pressure water to said nozzle means.
 8. Apparatus as recited in claim 7, wherein said nozzle means further includes: a mounting cylinder disposed to extend vertically beneath said hopper bottom wall opening; a hollow shaft rotatably mounted within said mounting cylinder, and having an enlarged head on the upper end thereof, the lower end of said hollow shaft extending to the exterior of said sump, and said enalarged head being disposed above said hopper bottom wall; and connector means rotatably mounted on said extended lower end of said hollow shaft for transmitting high pressure water thereto, said nozzle being mounted on said hollow shaft below said enlarged head and being in communication with said connector means. 